Stretchable device

Abstract

Provided is a stretchable device that comprises a stretchable substrate, an electronic component that is mounted on the stretchable substrate, and a plurality of stretchable wires that are provided at least inside the stretchable substrate. As seen from the thickness direction, the stretchable substrate has a first region that coincides with the stretchable wires and a second region that coincides with the electronic component and does not coincide with the stretchable wires, and in a cross-section of the stretchable substrate taken where the stretchable wires are provided, the second region is thicker than the first region. At least one of the stretchable wires has a first portion that extends in a first direction that is the stretching direction of the stretchable wires and a second portion that is continuous with the first portion and extends in a second direction that is different from the first direction so as to be electrically connectable to the electronic component.

Description

stretchable devices

[0001] The present disclosure relates to stretchable devices.

[0002] Stretchable devices including a stretchable substrate and stretchable wiring have been known for some time. In these stretchable devices, electronic components that can be electrically connected to the stretchable wiring may be mounted.

[0003] Patent No. 6930681

[0004] A stretchable device may have a configuration in which a stretchable wiring is provided on a stretchable substrate and an electronic component is mounted on the stretchable wiring. In such a configuration, a structure may be adopted in which the portion other than the stretchable wiring connected to the electronic component is covered with the stretchable substrate, for example. In this case, the difference in thickness between the portion where the stretchable wiring and the stretchable substrate overlap and the portion where they do not overlap becomes large, and the stretchable device has a shape with a recess. In other words, the electronic component is placed in a recess with a relatively thin thickness.

[0005] The recessed portions are thinner than the portions of the stretchable device other than the recessed portions, and therefore may have lower stretch resistance. Therefore, when stress is applied to the stretchable wiring that is not covered with the stretchable substrate during stretching of the stretchable device, stress may be concentrated on the stretchable wiring due to the low stretch resistance of the recessed portions of the stretchable device. Such stress concentration may cause breakage of the stretchable wiring, making it impossible to properly implement electrical connection.

[0006] The present disclosure has been made in view of the above problem. That is, an object of the present disclosure is to provide a stretchable device that can suppress stress on a stretchable wiring caused by deformation of the stretchable device.

[0007] In order to achieve the above object, in one embodiment of the present disclosure, there is provided a stretchable device comprising: a stretchable substrate; an electronic component mounted on the stretchable substrate; and a plurality of stretchable wirings provided at least within the stretchable substrate, wherein the stretchable substrate has a first region that overlaps with the stretchable wiring when viewed from the thickness direction, and a second region that does not overlap with the stretchable wiring and overlaps with the electronic component, and in a cross-sectional view at a position where the stretchable wiring is arranged, the thickness of the second region is greater than the thickness of the first region, and at least one of the plurality of stretchable wirings has a first portion that extends in a first direction that is the stretch direction of the stretchable wiring, and a second portion that is continuous with the first portion and extends in a second direction different from the first direction so as to be electrically connectable to the electronic component.

[0008] According to a stretchable device according to an embodiment of the present disclosure, it is possible to suppress stress on the stretchable wiring caused by deformation of the stretchable device.

[0009] FIG. 1A is a top view schematically showing a stretchable device (before electronic components are mounted) according to a first embodiment of the present disclosure. FIG. 1B is a cross-sectional view (taken along the IB-IB cross section in FIG. 1A ) schematically showing a stretchable device (before electronic components are mounted) according to a first embodiment of the present disclosure. FIG. 1C is a cross-sectional view (taken along the IB-IB cross section in FIG. 1A ) schematically showing a stretchable device (before electronic components are mounted) according to a modified example of the first embodiment of the present disclosure. FIG. 2A is a top view schematically showing a stretchable device (with electronic components mounted) according to the first embodiment of the present disclosure. FIG. 2B is a cross-sectional view (taken along the IIB-IIB cross section in FIG. 2A ) schematically showing a stretchable device (with electronic components mounted) according to the first embodiment of the present disclosure. FIG. 3A is a top view schematically showing a stretchable device (with electronic components mounted) according to a second embodiment of the present disclosure. FIG. 3B is a cross-sectional view (taken along the IIIB-IIIB cross section of FIG. 3A ) schematically illustrating a stretchable device (with electronic components mounted) according to a second embodiment of the present disclosure. FIG. 4A is a top view schematically illustrating a stretchable device (with electronic components mounted) according to a third embodiment of the present disclosure. FIG. 4B is a cross-sectional view (taken along the IVB-IVB cross section of FIG. 4A ) schematically illustrating a stretchable device (with electronic components mounted) according to a third embodiment of the present disclosure. FIG. 5A is a top view schematically illustrating a stretchable device (with electronic components mounted) according to a fourth embodiment of the present disclosure. FIG. 5B is a cross-sectional view (taken along the VB-VB cross section of FIG. 5A ) schematically illustrating a stretchable device (with electronic components mounted) according to a fourth embodiment of the present disclosure. FIG. 6A is a top view schematically illustrating a stretchable device (with electronic components mounted) according to a fifth embodiment of the present disclosure. FIG. 6B is a cross-sectional view (at the VIB-VIB cross section of FIG. 6A ) schematically illustrating a stretchable device (with electronic components mounted) according to a fifth embodiment of the present disclosure. FIG. 6C is a top view schematically illustrating a stretchable device (with electronic components mounted) according to a fifth embodiment of the present disclosure. FIG. 6D is a cross-sectional view (at the VID-VID cross section of FIG. 6C ) schematically illustrating a stretchable device (with electronic components mounted) according to a fifth embodiment of the present disclosure. FIG. 7A is a schematic perspective view for explaining a method for manufacturing a stretchable device according to a first embodiment of the present disclosure. FIG. 7B is a schematic perspective view for explaining a method for manufacturing a stretchable device according to a first embodiment of the present disclosure.FIG. 7C is a schematic perspective view illustrating a method for manufacturing a stretchable device according to the first embodiment of the present disclosure. FIG. 7D is a schematic perspective view illustrating a method for manufacturing a stretchable device according to the first embodiment of the present disclosure. FIG. 7E is a schematic perspective view illustrating a method for manufacturing a stretchable device according to the first embodiment of the present disclosure. FIG. 7F is a schematic perspective view illustrating a method for manufacturing a stretchable device according to the first embodiment of the present disclosure. FIG. 8 is a diagram illustrating a difference in elongation rate relative to an initial length during elongation between a conventional stretchable device and a stretchable device according to the present disclosure. FIG. 9A is a top view schematically illustrating a stretchable device according to a sixth embodiment of the present disclosure (with electronic components mounted). FIG. 9B is a cross-sectional view (taken along the IXB-IXB cross section of FIG. 9A ) schematically illustrating a stretchable device according to the sixth embodiment of the present disclosure (with electronic components mounted). FIG. 10A is a top view schematically illustrating a stretchable device according to a seventh embodiment of the present disclosure (with electronic components mounted). FIG. 10B is a cross-sectional view (at XB-XB cross section in FIG. 10A ) schematically illustrating a stretchable device (electronic component mounted state) according to a seventh embodiment of the present disclosure. FIG. 10C is an enlarged view of a connection portion between an electronic component and a stretchable substrate in a stretchable device according to the seventh embodiment of the present disclosure. FIG. 11 is a cross-sectional view schematically illustrating a modified example of a stretchable device (electronic component mounted state) according to the seventh embodiment of the present disclosure. FIG. 12 is a cross-sectional view schematically illustrating a modified example of a stretchable device (electronic component mounted state) according to the seventh embodiment of the present disclosure. FIG. 13A is a top view schematically illustrating a stretchable device (electronic component mounted state) according to an eighth embodiment of the present disclosure. FIG. 13B is a cross-sectional view (at XIIIB-XIIIB cross section in FIG. 13A ) schematically illustrating a stretchable device (electronic component mounted state) according to the eighth embodiment of the present disclosure. FIG. 13C is an enlarged view of a connection portion between an electronic component and a stretchable substrate in a stretchable device according to the eighth embodiment of the present disclosure.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each embodiment, differences from those previously described will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment. Among the components in the following embodiments, components not recited in independent claims will be described as optional configurations. Furthermore, the size and size ratios of components shown in the drawings are not necessarily strict. Furthermore, in each figure, substantially identical components are assigned the same reference numerals, and duplicated descriptions may be omitted or simplified.

[0011] In this specification, the "stretching direction" means that, from the viewpoint of more reliably preventing short circuits during use of the stretchable device, the stretching direction of the stretchable substrate and stretchable wiring is preferably the longitudinal direction of the stretchable device, but they do not have to be stretched in one direction.

[0012] In addition, "flush" in this specification does not only mean that the two surfaces are flat with no steps or irregularities between them, but can also include a tolerance of + / - 1%. In other words, "flush" means that the two surfaces are not completely flat, and some steps are allowed. Furthermore, "non-stepped form" refers to a form in which the main surfaces of the stretchable device do not have a stepped height difference, that is, a step, and can be, for example, a flat form or a form without irregularities.

[0013] In this specification, the term "stretchable wiring" includes a conductive structure such as a via conductor for ensuring conduction within a stretchable substrate or between substrates. The stretchable wiring and the via conductor may be collectively referred to as a "conductive portion."

[0014] [First Embodiment] The structure of a stretchable device according to a first embodiment will be described with reference to FIGS. 1A, 1B, and 1C. FIG. 1A is a top view schematically illustrating a stretchable device 100 according to the present disclosure (before electronic components are mounted). FIG. 1B is a cross-sectional view of the stretchable device of FIG. 1A taken along the line IB-IB. FIG. 1C is a cross-sectional view schematically illustrating a modified example of FIG. 1B. FIGS. 2A and 2B are a top view and a cross-sectional view of a stretchable device 100 according to a first embodiment of the present disclosure (in a state where an electronic component is mounted) in which an electronic component 70 is mounted on the first main surface 1 of the stretchable device 100 of FIGS. 1A and 1B. Note that the cross-sectional views in this specification are views based on a cross section in the thickness direction of the stretchable substrate. Actual comparisons can also be confirmed by the above-described cross-sectional view at any position of a stretchable wiring stretching in one direction.

[0015] First, the basic components of the stretchable device according to the first embodiment of the present disclosure will be described.

[0016] The stretchable device 100 according to the first embodiment of the present disclosure includes a stretchable substrate 10, an electronic component 70 mounted on the stretchable substrate 10, and a plurality of stretchable wirings 20. The plurality of stretchable wirings 20 are provided at least within the stretchable substrate 10.

[0017] The first main surface 1 (corresponding to the top surface) of the stretchable device can be a mounting surface on which an electronic component 70 is mounted, as shown in Figures 1A and 1B. That is, the electronic component 70 can be mounted on the first main surface 1 of this stretchable device 100 (see Figures 2A and 2B).

[0018] The basic components of the stretchable device 100 and the electronic component 70 that can be mounted on the stretchable device 100 will be specifically described below.

[0019] (Stretchable substrate 10) The stretchable substrate 10 is a sheet-like or film-like stretchable substrate, and is made of, for example, a stretchable resin material. The resin material of the stretchable substrate 10 is not particularly limited, but examples thereof include thermoplastic polyurethane (TPU), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), etc.

[0020] (Stretchable Wiring 20) The stretchable wiring 20 contains conductive particles and a resin. The stretchable wiring 20 is not particularly limited, but examples thereof include a mixture of conductive particles such as metal powder of Ag (silver), Cu (copper), Ni (nickel), or the like, and an elastomer resin such as a silicone resin. The average particle size of the conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. Furthermore, the conductive particles are preferably spherical, but may also be flat powder or have a structure with protrusions to improve stretchability.

[0021] The thickness of the stretchable wiring 20 is not particularly limited, but is preferably 100 μm or less, and more preferably 50 μm or less. The thickness of the stretchable wiring 20 is preferably 0.01 μm or more, which is the stretch resistance. The line width of the stretchable wiring 20 is not particularly limited, but is preferably 0.1 μm or more, and more preferably 10 mm or less.

[0022] (Electronic Component 70) The electronic component 70 can be various electronic components used depending on the application of the stretchable device 100. By way of example only, the electronic component 70 may be an LED, a thermistor, an illuminance sensor, a color sensor, a field effect transistor (FET), an operational amplifier, a capacitor, a piezoelectric speaker, a strain gauge, or the like. For example, the electronic component 70 may be configured to include a sensor according to the type of signal to be acquired.

[0023] (Characteristic Portions of the First Embodiment) Based on the details of the main components of the stretchable device 100 described above, the characteristic portions of the first embodiment will be described below.

[0024] 1A to 2B, in the first embodiment, at least one of the multiple stretchable wirings 20 has a first portion 21 and a second portion 23 continuous with the first portion. Note that the first portion 21 and the second portion 22 are preferably made of the same material, but may be made of different materials.

[0025] Specifically, in a cross-sectional view, the longitudinal portion of the first portion 21 of the stretchable wiring 20 extends along a first direction, which is the extension direction (or width direction) of the main surface of the stretchable device 100. Furthermore, one end of the second portion 23 is continuous with one end of the first portion 21 of the stretchable wiring 20, and extends in a second direction (for example, the thickness direction) different from the first direction, so as to be able to come into contact with the electronic component 70. At this time, an end face 24 of the second portion 23 of the stretchable wiring 20 is able to be electrically connected to the electronic component 70.

[0026] By adopting such a configuration, the stretchable wiring 20 can have a bent or curved form as a whole. Note that, although the extension direction of the first portion 21 of the stretchable wiring 20 and the longitudinal direction of the stretchable device 100 coincide with each other in FIG. 1B , they do not necessarily have to coincide with each other. Furthermore, in the exemplary first embodiment (before electronic components are mounted) shown in FIG. 1B , the first main surface 1 is positioned on the upper side in the thickness direction of the stretchable substrate 10, but this is not limited to this and the first main surface 1 may also be positioned on the lower side. Specifically, the second portion 23 of the stretchable wiring 20 may extend to a second main surface 3 opposite the first main surface 1, and an end surface 24 of the second portion 23 may be positioned on the second main surface 3.

[0027] The stretchable substrate 10 has a first region (corresponding to 11 in FIG. 1B ) that overlaps with the stretchable wiring 20 when viewed from the thickness direction and is located directly below the first portion 21 of the stretchable wiring 20, and a second region (corresponding to 12 in FIG. 1B ) that does not overlap with the stretchable wiring 20 and overlaps with the electronic component 70. In addition, in a cross-sectional view at the location where the stretchable wiring 20 is arranged, the thickness of the second region 12 is greater than the thickness of the first region 11. Specifically, the thickness h of the second region 12 ｙ and the thickness h of the first region 11 ｘ２ The relationship between h ｙ >h ｘ２ It is characterized by the fact that

[0028] Furthermore, the stretchable substrate 10 may have a third region (corresponding to 13 in FIG. 1B) located directly above the first portion 21 of the stretchable wiring 20. The thickness of the third region in this case is h ｘ１ Then, h ｙ >h ｘ１ +h ｘ２ It is preferable that, for example, h ｙ= (h ｘ１ +h ｘ２ + thickness T of the first portion 21 of the elastic wiring 20 ２ ) relationship.

[0029] That is, the range of the second region 12 is from the second main surface 3 of the stretchable substrate 10 to the upper side of the first portion 21 of the stretchable wiring 20, and is not positioned on the same line as or below the first portion 21 of the stretchable wiring 20. In other words, the second portion 23 of the stretchable wiring 20 and the second region 12 of the stretchable substrate 10 are in contact with each other.

[0030] In this regard, when the thickness of the second region 12 of the stretchable substrate 10 that overlaps with the electronic component 70 is the same as or smaller than the thickness of the first region 11 that overlaps with the stretchable wiring 20 in the thickness direction of the stretchable substrate 10, as described in the Technical Problems section of the present application, a relatively thin recessed portion in which the electronic component 70 can be placed can be formed in the stretchable device 100 (specifically, in the stretchable substrate 10 in this embodiment). In this case, due to the low stretch resistance of the recessed portion of the stretchable device 100, stress is concentrated in the stretchable wiring 20, and there is a risk that the stretchable wiring 20 will break.

[0031] In contrast, in the present disclosure, the thickness h of the second region 12 that overlaps with the electronic component 70 of the stretchable substrate 10 in the thickness direction of the stretchable substrate 10 is ｙ The thickness h of the first region 11 overlapping with the elastic wiring 20 ｘ２ is larger than . Therefore, in the second region 12 of the stretchable substrate 10 located directly below the electronic component 70, it is easy to ensure a contact area between the side surface (corresponding to the surface facing the side surface 26) of the second part 23 of the stretchable wiring 20 and the stretchable substrate 10. As a result, it is possible to reduce the difference in thickness between the second region 12 that overlaps with the electronic component 70 of the stretchable substrate 10 and the first region 11 that overlaps with the stretchable wiring 20. This allows the portion where the electronic component 70 can be placed to have a relatively large thickness, and no recess is formed.

[0032] For these reasons, it is possible to maintain the stretch resistance of the stretchable device 100, specifically the stretch resistance of the stretchable substrate 10, compared to the conventional case in which the electronic component 70 is placed in a relatively thin recess in the stretchable device 100 and electrically connected to the stretchable wiring 20.

[0033] This makes it possible to uniformly distribute the stress applied to the stretchable device 100 when the stretchable device 100 is stretched along the extension direction of the main surface of the stretchable device 100. As a result, it is possible to alleviate stress concentration on the stretchable wiring 20, suppress the occurrence of physical damage such as breakage of the stretchable wiring 20, and increase the durability of the stretchable device 100.

[0034] The alleviation of stress concentration on the stretchable wire 20 when the stretchable device 100 is stretched along the extension direction of the main surface can reduce errors in the signal transmitted by the stretchable wire 20. In this respect, a highly accurate stretchable device 100 can be provided.

[0035] Furthermore, because electronic components are not placed in the recesses of the stretchable device as in the past, the size of the stretchable substrate 10 of the stretchable device 100 according to the present disclosure can be suitably secured by the spatial size of the recesses compared to the past. As a result, when the same stress is generated in the stretchable device 100, the stress applied to the stretchable substrate 10 can be relatively smaller compared to the past, and the maximum stress that the stretchable device 100 can withstand when stretching can also be increased. Therefore, this can also contribute to obtaining a stretchable device 100 with high stretching strength and durability.

[0036] The sum of the thickness of the second region 12, the thickness of the first region 11 and the third region 13, and the thickness of the elastic wiring 20 (i.e., h ｘ１ +h ｘ２ + thickness T of the elastic wiring 20 ２ ) is smaller, it is possible to make the thickness between one first main surface 1 (corresponding to the upper main surface) of the stretchable device 100 and the other second main surface 3 (corresponding to the lower main surface) opposite thereto approximately the same as a whole.

[0037] In particular, it is preferable that the end face 24 of the second portion 23 of the stretchable wiring 20 is positioned on the first main surface 1 of the stretchable device 100 ( FIG. 1C ). In other words, there are cases where the first main surface 1 of the stretchable device 100, on which the end face 24 of the second portion 23 of the stretchable wiring 20 that can be electrically connected to the electronic component 70 is positioned, can have a non-step form. Specifically, in the modified example of the first embodiment shown in FIG. 1C , on the first main surface 1 (corresponding to the upper surface) of the stretchable device 100, the first main surface 1 of the stretchable substrate 10 and the second portion 23 of the stretchable wiring 20 can be flush with each other, and the first main surface 1 of the stretchable substrate 10 can be on the same plane without any steps. This can improve the mountability of the electronic component 70 via solder or the like to the second portion 23 of the stretchable wiring 20 that is positioned on the first main surface 1 of the stretchable device 100.

[0038] Here, "the thickness between one first main surface 1 of the stretchable device 100 and the other opposing second main surface 3 is approximately the same" will be specifically explained. In the stretchable device 100, the total thickness H1 at a portion where the second portion 23 of the stretchable wiring 20 is located, the total thickness H2 at a portion where only the stretchable substrate 10 is present and no stretchable wiring 20 is present, and the total thickness H3 at a portion where only the first portion 21 of the stretchable wiring 20 is located can be approximately the same (see FIG. 1C ). More specifically, for each of the above total thicknesses H1 to H3, each total thickness may be 0.1 mm or more and 0.2 mm or less, or 0.12 mm or more and 0.15 mm or less, and may be, for example, 0.12 mm.

[0039] Furthermore, the above-mentioned "substantially the same" refers to a form in which the end face 24 of at least one stretchable wiring 20 is in contact with the electronic component 70, while the first main surface 1 (for example, the main surface of the stretchable substrate) of the stretchable device 100 adjacent to the stretchable wiring 20 and located directly below the electronic component 70 is not in direct contact with the electronic component 70. Specifically, this encompasses the extent to which the side surface of the second portion 23 of the stretchable wiring 20 (corresponding to the surface facing the side surface 26) and the second region 12 of the stretchable substrate 10 can come into contact with each other.

[0040] Furthermore, "substantially the same total thickness" refers to a difference in thickness of 0.02 mm or less, preferably 0.01 mm or less, and more preferably refers to a completely identical thickness between one first main surface 1 of the stretchable device 100 and the other opposing second main surface 3. In other words, when the first main surface 1 is not completely flat or flush, and the difference is within the above-mentioned range, it falls within the category that can be said to have a substantially identical total thickness.

[0041] The end face 24 of the second portion may have a diameter of 10 μm or more and approximately 30 μm or less, and is particularly preferably 15 μm. The end face 24 of the second portion of the stretchable wiring 20 can be located on the uppermost surface of the stretchable substrate 10, or can be located above the uppermost surface. That is, the first main surface 1 of the stretchable substrate 10 can be located below the end face 24 of the stretchable wiring 20. The "uppermost surface" refers to the uppermost surface on the first main surface 1 side of the stretchable substrate 10, but these directions do not necessarily have to coincide with the top and bottom of the stretchable device 100 when in use.

[0042] Furthermore, in such a structure, as described above, the elastic wiring 20 has a shape that is bent or curved as a whole, so that the thickness T １ The thickness T of the elastic wiring 20 at a portion corresponding to the width of the first portion 21 ２ (See FIG. 2B). １ , the end surface 24 of the second portion can be located on the first main surface 1 of the stretchable device 100, and as a result, the above-mentioned total thickness H1 can be the same thickness as H2 and H3.

[0043] 2A and 2B , the electronic component 70 can be disposed so that the stretchable wiring 20 and the electronic component 70 can be electrically connected. Although not shown, the electronic component 70 may be connected to the stretchable wiring 20 by solder and / or a conductive adhesive or the like. Alternatively, the electronic component 70 may be directly connected to the stretchable wiring 20. Note that the electronic component 70 may be mounted on the first main surface 1 of the stretchable device 100.

[0044] When the electronic component 70 is mounted on the first main surface 1, in a cross-sectional view, the side surface 26 of the second portion 23 of the stretchable wiring 20 (i.e., the side surface that is continuous with the end surface 24 of the second portion 23 and extends in the thickness direction of the stretchable substrate 10) can be flush with the side surface of the electronic component 70. In this case, the side surface 26 of the second portion 23 is not located outside the side surface of the electronic component 70.

[0045] From another perspective, when the electronic component 70 is connected to the end surface 24 of the second portion 23 of the stretchable wiring 20, the side surface 2 of the stretchable device 100 and the electronic component 70 do not face each other. In other words, the side surface 2 of the stretchable device 100 and the side surface of the electronic component 70 are separated from each other and are not in contact with each other.

[0046] According to this configuration, the stress applied to the stretchable wiring 20 due to expansion and contraction is reduced as described above, and therefore the stress applied to the connection surface of the solder and / or conductive adhesive, etc. that connects the electronic component 70 and the stretchable wiring 20 is also reduced. Therefore, it is possible to reduce the possibility of problems such as the electronic component 70 becoming detached or falling due to peeling or splitting between the stretchable wiring 20 and the solder and / or conductive adhesive, etc.

[0047] A method for producing the stretchable device 100 according to the first embodiment (corresponding to the basic embodiment) will be described below.

[0048] First, the stretchable substrate 10 is prepared, and a through hole 4 extending in the thickness direction of the stretchable substrate 10 is formed in the stretchable substrate 10 by laser processing or the like. Thereafter, the formed through hole 4 is filled with a conductive paste that will be the source of the stretchable wiring 20, thereby forming a second portion 23 of the stretchable wiring (see FIGS. 7A to 7C ). This second portion 23 is formed so as to extend in the thickness direction of the stretchable substrate 10.

[0049] Furthermore, after preparing another stretchable substrate 10, a first portion 21 of the stretchable wiring 20 extending along the extension direction of the main surface of the stretchable substrate 10 is formed on the main surface of the stretchable substrate 10 by screen printing (see Figures 7D and 7E).

[0050] Thereafter, a stretchable substrate 10 having a first portion 21 is positioned on the lower side, and another stretchable substrate 10 having a second portion 23 is positioned on the upper side, and the two stretchable substrates are overlapped so that one end of the first portion 21 and one end of the second portion 23 are continuous with each other. In this manner, the stretchable device 100 shown in FIGS. 1A and 1B can be produced (see FIG. 7F ). Thereafter, an electronic component 70 is further disposed on the first main surface 1 of the stretchable device 100, in this embodiment, straddling the first main surface 1 of the stretchable substrate 10 and the end face of the stretchable wiring 20 of the stretchable device 100, so that the end face 24 of the second portion 23 of the stretchable wiring 20 and the electronic component 70 are electrically connectable.

[0051] The obtained stretchable device 100 has a thickness h of the second region 12 in a cross-sectional view at the location where the stretchable wiring 20 is disposed. ｙ is the thickness h of the first region 11 ｘ２ Specifically, in the first embodiment, it is possible to make the thickness between one first main surface 1 (corresponding to the upper main surface) of the stretchable device 100 and the other opposing second main surface 3 (corresponding to the lower main surface) approximately the same as one another.

[0052] Therefore, since electronic components are not placed in the recesses of the stretchable device as in the past, the stretch resistance of the stretchable device 100, specifically the stretch resistance of the stretchable substrate 10, can be maintained compared to when the stretchable wiring is electrically connected to the electronic components in this recess.

[0053] This makes it possible to uniformly distribute the stress applied to the stretchable device 100 when the stretchable device 100 is stretched along the extension direction of the main surface of the stretchable device 100. As a result, it is possible to alleviate stress concentration on the stretchable wiring 20, suppress the occurrence of physical damage such as breakage of the stretchable wiring 20, and increase the durability of the stretchable device 100.

[0054] [Second Embodiment] Hereinafter, the configuration of a stretchable device 100 (with electronic components mounted) according to a second embodiment will be described with reference to Figures 3A and 3B. The second embodiment differs from the first embodiment in that it includes a stretchable substrate cover member 30 that covers the stretchable substrate 10. Figure 3A is a top view schematically showing the stretchable device 100 according to the second embodiment of the present disclosure. Figure 3B is a cross-sectional view of the stretchable device of Figure 3A taken along line IIIB-IIIB.

[0055] Furthermore, when producing the stretchable device 100 of the second embodiment, it differs from the production method of the first embodiment in that it includes a step of preparing a stretchable substrate cover member 30 in place of the upper stretchable substrate 10, and forming through holes 4 extending in the thickness direction of the stretchable substrate 10 in the stretchable substrate cover member 30 by laser processing or the like. By producing it by this method, it is possible to produce the stretchable device 100 according to the second embodiment, which further includes the stretchable substrate cover member 30 that covers the stretchable substrate 10 and the stretchable wiring 20.

[0056] The stretchable device 100 according to the second embodiment of the present disclosure includes a plurality of electronic components 70, stretchable substrates 10, and stretchable wirings 20, and further includes a stretchable substrate cover member 30 that covers the stretchable substrates 10 and the stretchable wirings 20. Note that the end face 24 of the second portion and the main surface of the stretchable substrate cover member 30 may be flush with each other. The components will be described in detail below.

[0057] (Stretchable substrate cover member 30) The stretchable substrate cover member 30 is a sheet-like or film-like stretchable substrate similar to the stretchable substrate 10, and is made of, for example, a stretchable resin material. The material of the stretchable substrate cover member 30 is not particularly limited, but examples thereof include resin materials such as styrene-based resins, olefin-based resins, PVC-based resins, urethane-based resins, ester-based resins, and amide-based resins. It may also be formed by applying or printing a paste or ink-like material, or by thermocompression bonding a film- or sheet-like material. For example, the thickness of the stretchable substrate cover member 30 is not particularly limited, but is preferably 20 μm or more, and more preferably 40 μm or more.

[0058] The stretchable substrate 10 and the stretchable wiring 20 may be covered by a stretchable substrate cover member 30. The stretchable substrate cover member 30 only needs to cover the first portion 21 of the stretchable wiring 20 so that the entirety of the first portion 21 is not exposed. For example, the stretchable substrate cover member 30 may cover the outer surfaces of the stretchable substrate 10 and the stretchable wiring 20. That is, the stretchable substrate cover member 30 may cover the second region 12 of the stretchable substrate 10 so as to be directly below the electronic component 70 and in contact with the side surface of the second portion 23 of the stretchable wiring 20 (the side surface opposite the side surface 26).

[0059] Furthermore, the material of the stretchable substrate cover member 30 may be selected depending on the application of the electronic component 70. For example, by selecting a heat-resistant material that has a higher glass transition point than the stretchable substrate 10, the heat resistance of the stretchable device 100 can be improved. Therefore, for example, when a heat-dissipating and heat-generating electronic component 70 is mounted, it is possible to protect the stretchable substrate 10 from heat.

[0060] Furthermore, the stretchable substrate cover member 30 is preferably made of a material that can withstand chemical solutions (e.g., strong acids, strong alkalis, acetone, etc.) that can chemically attack the stretchable substrate 10, or is preferably made of a material that protects the stretchable substrate 10, which can be deformed by humidity. In other words, by selecting a material with a drug reactivity or water vapor permeability lower than that of the stretchable substrate 10, the water resistance and chemical resistance of the stretchable device 100 can be improved.

[0061] 3A and 3B, the end surface 24 of the second portion of the stretchable wiring 20 and the electronic component 70 may be connected by solder and / or a conductive adhesive, etc. In addition, the stretchable substrate cover member 30 and the stretchable wiring 20 may be bonded by thermal bonding or adhesive.

[0062] As described in the first embodiment, the stretchable wiring 20 and the electronic component 70 are connected by applying heat and using soldering and / or a conductive adhesive or the like, but the heat or a chemical solution such as the conductive adhesive may impose a thermal or chemical load on the stretchable substrate 10. Therefore, for example, by covering the stretchable substrate 10 and the stretchable wiring 20 with a heat-resistant stretchable substrate cover member 30, it may be possible to reduce the thermal load.

[0063] The stretchable substrate cover member 30 is also bonded to the stretchable substrate 10 by thermal bonding or the like, but the temperature during thermal bonding is lower than the soldering temperature, so the amount of heat applied to the stretchable substrate 10 and the stretchable wiring 20 is reduced. For example, after the heat-resistant stretchable substrate cover member 30 is bonded by thermal bonding to cover the stretchable substrate 10 and the stretchable wiring 20, when the electronic component 70 and the stretchable wiring 20 are connected by solder, heat is not directly applied to the stretchable wiring 20 and the stretchable substrate 10, and the thermal load can be reduced. Therefore, heat damage to the stretchable substrate 10 can be reduced, and the reliability of the stretchable substrate 10 can be increased accordingly.

[0064] [Third embodiment] Hereinafter, the configuration of a stretchable device (electronic component mounted state) according to a third embodiment will be described with reference to Fig. 4A and Fig. 4B. Compared to the first embodiment, the third embodiment differs in that a part 22 of the first portion of the stretchable wiring 20 is exposed. Fig. 4A is a top view schematically showing a stretchable device according to a third embodiment of the present disclosure. Fig. 4B is a cross-sectional view of the stretchable device of Fig. 4A at the IVB-IVB cross section.

[0065] Furthermore, when producing the stretchable device of the third embodiment, it differs from the first embodiment in that it includes a step of cutting out the stretchable substrate 10 superimposed on the upper side with a cutting tool, a laser, or the like, to expose a part 22 of the first portion. By producing it by this method, it is possible to produce the stretchable device 100 according to the third embodiment, which includes a plurality of stretchable substrates 10 and stretchable wirings 20, and in which a part 22 of the first portion of the stretchable wiring 20 is exposed.

[0066] The stretchable device 100 according to the third embodiment of the present disclosure includes a plurality of electronic components 70, stretchable substrates 10, and stretchable wirings 20, and a part 22 of the first portion of the stretchable wiring 20 is exposed.

[0067] The stretchable substrate 10 may be partially cut out in the stretch direction, exposing a portion 22 of the first portion of the stretchable wiring 20, and the exposed portion of the first portion 22 may be used as an electrode 25. Therefore, by connecting the portion 22 of the first portion (i.e., the electrode 25) to another stretchable wiring or an electronic component, an electrical connection is possible, and an electrical signal can be sent throughout the circuit. Note that, since the portion 22 of the first portion of the stretchable wiring 20 is used to connect to another stretchable wiring or an electronic component, its width may be approximately 0.1 mm or more and 1 μm or less.

[0068] In the third embodiment, the stretchable substrate 10 and the stretchable wiring 20 may be covered by a stretchable substrate cover member 30 in the same manner as in the second embodiment.

[0069] [Fourth embodiment] Hereinafter, the configuration of a stretchable device (with electronic components mounted) according to a fourth embodiment will be described with reference to Figs. 5A and 5B. The fourth embodiment differs from the first embodiment in that it uses a light-blocking sheet or the like. Fig. 5A is a top view schematically showing a stretchable device according to a fourth embodiment of the present disclosure. Fig. 5B is a cross-sectional view of the stretchable device of Fig. 5A taken along the VB-VB cross section.

[0070] Furthermore, when producing the stretchable device of the fourth embodiment, it differs from the production method of the first embodiment in that it includes a step of preparing a light-shielding sheet 40 instead of the upper stretchable substrate 10, and forming through holes 4 in them by laser processing or the like. By producing it by this method, it is possible to produce the stretchable device 100 according to the fourth embodiment, which further includes a light-shielding sheet 40 (or a heat-insulating sheet or the like) that covers the stretchable substrate 10 and the stretchable wiring 20.

[0071] The stretchable device 100 according to the fourth embodiment of the present disclosure includes a plurality of electronic components 70, stretchable substrates 10, and stretchable wirings 20, and further includes a light-shielding sheet 40 that covers the stretchable substrates 10 and the stretchable wirings 20. The components will be specifically described below.

[0072] (Light-shielding sheet 40) The light-shielding sheet 40 is a sheet-like or film-like stretchable substrate similar to the stretchable substrate 10, and is made of, for example, a stretchable material. The light-shielding sheet 40 is made of a material having a lower light transmittance than the stretchable substrate 10, and examples of the material include polyolefin-based, polyester-based, and vinyl chloride-based resin materials.

[0073] Alternatively, the light-shielding sheet may be a heat insulating sheet or a color sheet. That is, a heat insulating sheet or a color sheet covering the stretchable substrate 10 and the stretchable wiring 20 may be further provided. The material of the heat insulating sheet is a material having higher heat insulating properties than the stretchable substrate 10, and is not particularly limited, but examples thereof include aluminum-based materials with high thermal reflectivity, and urethane-based, phenol-based, and polystyrene-based materials with low thermal conductivity. The color sheet is also not particularly limited as long as it is a material with a color different from that of the stretchable substrate 10 and the stretchable wiring 20. On the other hand, the material must be resistant to the heat and chemicals used when joining the electronic component 70, and is required to have resistance equal to or greater than that of the stretchable substrate 10 and the stretchable wiring 20. The above-mentioned sheets, etc. may be formed by applying or printing a paste or ink-like material, or by thermocompression bonding a film or sheet-like material.

[0074] The thickness of the light-shielding sheet 40 etc. is not particularly limited, but may be 10 μm or more and 40 μm or more, and is preferably 20 μm or less from the viewpoint of transparency, durability, heat resistance, etc.

[0075] The stretchable substrate 10 and the stretchable wiring 20 may be covered by a light-shielding sheet 40 or the like, or a part 22 of the first part of the stretchable wiring 20 may be exposed as in the third embodiment. As in the case of covering with the stretchable substrate cover member 30, the light-shielding sheet 40 or the like may be flush with the end face 24 of the second part, or the first main surface 1 of the stretchable device 100. In other words, the first main surface 1 of the stretchable device 100 on which the end face 24 of the second part 23 of the stretchable wiring 20 is positioned may have a non-step shape.

[0076] From another perspective, the stretchable substrate 10 and the stretchable wiring 20 may be covered by the light-shielding sheet 40 or the like so that the entire first portion 21 of the stretchable wiring 20 is not exposed. For example, the light-shielding sheet 40 may cover the outer surfaces of the stretchable substrate 10 and the stretchable wiring 20. That is, the light-shielding sheet 40 may cover the second region 12 of the stretchable substrate 10 so as to be directly below the electronic component 70 and in contact with the side surface of the second portion 23 of the stretchable wiring 20 (the side surface opposite the side surface 26).

[0077] For example, when the electronic component 70 is a light-emitting component such as an LED, and a living body or the like is present on the electronic component 70 side, and the electronic component 70 is made to emit light and applied to the living body, there are cases in which light is transmitted to the other main surface 3 opposite the first main surface 1 of the stretchable device 100. As a result, the desired amount of light cannot be applied to the living body, and accurate data cannot be measured. However, with the configuration of the present disclosure, by covering the stretchable substrate 10 and the stretchable wiring 20 with a light-shielding sheet 40, the light emitted from the LED is blocked by the first main surface 1, and the light does not transmit or reach the other main surface 3 opposite the first main surface 1, which can contribute to accurate data acquisition. Similarly, even when the electronic component 70 is a temperature measurement sensor such as a thermistor, covering the stretchable substrate 10 and the stretchable wiring 20 with a heat-insulating sheet can insulate heat from reaching the other second main surface 3 opposite the first main surface 1, which can contribute to accurately acquiring the temperature of the object to be measured.

[0078] Furthermore, by covering the stretchable substrate 10 and the stretchable wiring 20 with a color sheet, it is possible to easily identify the location where the electronic component 70 is placed. Therefore, the visibility of the placement position can be improved, and the sheet can function as a mark for distinguishing between the front and back of the stretchable substrate.

[0079] 6A to 6D, the configuration of a stretchable device according to a fifth embodiment will be described. The fifth embodiment differs from the first embodiment in that it uses an electronic component cover member 80 that protects the electronic component 70.

[0080] Fig. 6A is a top view schematically showing a stretchable device (electronic component mounted state) according to a fifth embodiment of the present disclosure. Fig. 6B is a cross-sectional view (at the VIB-VIB cross section of Fig. 6A) schematically showing a stretchable device (electronic component mounted state) according to a fifth embodiment of the present disclosure. Fig. 6C is a top view schematically showing a stretchable device (electronic component mounted state) according to a fifth embodiment of the present disclosure. Fig. 6D is a cross-sectional view (at the VID-VID cross section of Fig. 6C) schematically showing a stretchable device (electronic component mounted state) according to a fifth embodiment of the present disclosure.

[0081] Furthermore, when producing the stretchable device of the fifth embodiment, it differs from the production method of the first embodiment in that it includes a step of dropping an electronic component cover member 80 that covers the electronic component 70. By producing it by this method, it is possible to produce the stretchable device 100 according to the fifth embodiment that includes the electronic component cover member 80 that covers the electronic component 70.

[0082] The stretchable device 100 according to the fifth embodiment of the present disclosure includes a plurality of electronic components 70, stretchable substrates 10, and stretchable wirings 20, and further includes an electronic component cover member 80 that covers the electronic components 70. The components will be specifically described below.

[0083] (Electronic component cover member 80) The constituent material of the electronic component cover member 80 is not particularly limited, but examples thereof include acrylic resins, epoxy resins, olefin resins, urethane acrylate resins, and silicone resins. From the viewpoint of protecting the electronic component mounting portion, it is preferable that the Young's modulus of the resin used as the material for the electronic component cover member 80 is higher than that of the stretchable substrate. In addition, it is preferable that the resin is non-reactive with the stretchable substrate 10, the stretchable substrate cover member 30, and the like that may come into contact with the electronic component cover member 80.

[0084] In the stretchable device 100 according to the fifth embodiment, the stretchable substrate 10 and the stretchable wiring 20 may be covered by a stretchable substrate cover member 30, a light-shielding sheet 40, or the like, and a portion 22 of the first part of the stretchable wiring 20 may be exposed (see Figures 6C and 6D).

[0085] The electronic component cover member 80 is disposed to cover the electronic component 70 in order to protect the electronic component 70 from thermal or mechanical shock and to provide electrical insulation, etc. It is preferable to cover the entire electronic component 70, but it may also cover only a portion of it.

[0086] The electronic component cover member 80 also serves to protect the electronic components 70 from thermal or mechanical shocks and to provide electrical insulation.

[0087] On the other hand, the electronic component cover member 80 may react when it comes into contact with the stretchable wiring 20, and so the material can be limited. However, in the case of a structure in which the end face 24 of the second portion 23 of the stretchable wiring 20 is positioned on the first main surface 1 of the stretchable device 100 (corresponding to a structure in which the stretchable device shape of FIG. 1C is provided with an electronic component 70 and an electronic component cover member 80), the end face 24 of the second portion is not outside the electronic component 70, and the stretchable wiring 20 is not in contact with the electronic component cover member 80, so the electronic component cover member 80 and the stretchable wiring 20 cannot react.

[0088] In other words, since there is no need to consider the reactivity between the materials of the electronic component cover member 80 and the stretchable wiring 20, this can contribute to expanding the range of options for the electronic component cover member 80. Therefore, the electronic component cover member 80 can be selected by considering only the reactivity with the stretchable substrate 10. For example, a silicone-based material that is more resistant to thermal or mechanical shock can also be used as the electronic component cover member 80. As a result, it may be possible to reduce the placement spacing designed in consideration of the heat applied to the electronic component 70 from other electronic components, which can contribute to reducing the area of ​​the electronic component cover member 80 and the stretchable device 100. Therefore, the smaller area of ​​the electronic component cover member 80 increases the stretchable region of the stretchable substrate 10, which can improve stretchability.

[0089] Furthermore, the stretchable substrate 10 and the stretchable wiring 20 may be covered with a stretchable substrate cover member 30, a light-shielding sheet 40, or the like. In this case, if the end surface 24 of the second part 23 of the stretchable wiring 20 is structured to be positioned on the first main surface 1 of the stretchable device 100, it is only necessary to select an optimal electronic component cover member 80 that is non-reactive with each sheet member, which can also contribute to widening the range of combinations.

[0090] 9A and 9B, the configuration of a stretchable device according to a sixth embodiment will be described. Compared to the first embodiment, the sixth embodiment differs in that a sealing material 91 that surrounds the electronic component 70 is further provided on the main surface of the stretchable substrate 10.

[0091] FIG. 9A is a top view schematically showing a stretchable device (electronic component mounted state) according to a sixth embodiment of the present disclosure. FIG. 9B is a cross-sectional view (at the IXB-IXB cross section of FIG. 9A ) schematically showing a stretchable device (electronic component mounted state) according to the sixth embodiment of the present disclosure. Furthermore, when producing the stretchable device according to the sixth embodiment, it differs from the production method according to the first embodiment in that it includes a step of providing a sealing material 91 that surrounds the electronic component 70 on the main surface 1 of the stretchable substrate 10. By producing it by this method, it is possible to produce a stretchable device 100 according to the sixth embodiment, which further includes a sealing material 91 that surrounds the electronic component 70 on the main surface of the stretchable substrate.

[0092] The stretchable device 100 according to the sixth embodiment of the present disclosure includes an electronic component 70, a stretchable substrate 10, and a plurality of stretchable wirings 20, and further includes a sealing material 91 that surrounds the electronic component 70 on a main surface of the stretchable substrate 10. The components will be described in detail below. The components will be described in detail below.

[0093] (Sealing material 91) The sealing material 91 is a base material that seals the connection portion between the electronic component 70 and the elastic wiring 20. The constituent material of the sealing material 91 is not particularly limited, but examples thereof include acrylic resins, epoxy resins, olefin resins, urethane acrylate resins, and silicone resins.

[0094] The sealing material 91 is provided on the stretchable substrate 10 so as to surround the electronic component 70. This improves adhesion between the electronic component 70 and the stretchable substrate 10. From the viewpoint of preventing the electronic component 70 mounted on the stretchable substrate 10 from peeling off during expansion and contraction, the Young's modulus of the sealing material 91 is preferably greater than that of the stretchable substrate 10, specifically, preferably 300 MPa or greater. The improved adhesion increases resistance to external impacts, vibrations, and the like, and can prevent damage to the components. Furthermore, the improved heat dissipation efficiency can prevent overheating of the electronic component 70, maintaining stable operation. Furthermore, the risk of short circuits, such as poor contact at the connection between the electronic component 70 and the stretchable substrate 10, can be reduced. As a result, this can contribute to improving the reliability of the stretchable device 200.

[0095] From the viewpoint of protecting the electronic component 70, it is preferable that the outer contour of the sealing material 91 is located outside the outer contour of the electronic component 70 in a plan view. With such a configuration, the contact area between the sealing material 91 and the electronic component 70 increases, improving adhesion. Therefore, the larger the outer contour of the sealing material 91, the more effectively the electronic component 70 can be protected.

[0096] 10A to 10C, the configuration of a stretchable device 200 (electronic component mounted state) according to a seventh embodiment will be described. The seventh embodiment differs from the first embodiment in that a stretchable substrate laminate 10A is configured in which a plurality of stretchable substrates 10 are laminated in the thickness direction.

[0097] Fig. 10A is a top view schematically showing a stretchable device (electronic component mounted state) according to a seventh embodiment of the present disclosure. Fig. 10B is a cross-sectional view (at cross section XB-XB in Fig. 10A) schematically showing a stretchable device (electronic component mounted state) according to the seventh embodiment of the present disclosure. Fig. 10C is an enlarged view of a connection portion between an electronic component and a stretchable substrate in a stretchable device according to the seventh embodiment of the present disclosure.

[0098] Furthermore, when producing the stretchable device 200 of the seventh embodiment, it differs from the production method of the first embodiment in that it includes a step of stacking a plurality of stretchable substrates 10, and a step of providing a plurality of stretchable wirings 20, 20α as the stretchable substrates 10 are stacked. By producing using this method, it is possible to produce the stretchable device 200 of the seventh embodiment, which constitutes a stretchable substrate laminate in which a plurality of stretchable substrates 10 are stacked in the thickness direction. Note that in the stretchable device 200, as shown in FIG. 12 , the stretchable substrate laminate 10A may include an electronic component cover member 80.

[0099] The stretchable device 200 according to the seventh embodiment of the present disclosure includes an electronic component 70, a plurality of stretchable substrates 10, and stretchable wirings 20, 20α, and constitutes a stretchable substrate laminate 10A in which a plurality of stretchable substrates 10 are laminated in the thickness direction. The electronic component 70, the stretchable substrate 10, and the stretchable wirings 20 can be connected via a connecting member 90 (for example, solder, etc.).

[0100] Specifically, a stretchable wiring 20 having a first portion 21 and a second portion 23 is provided at least inside the stretchable substrate 10 on which the electronic component 70 is mounted. That is, at least a stretchable wiring 20 having the first portion 21 and the second portion 23 is provided in the uppermost layer and / or the lowermost layer of the stretchable substrate 10 constituting the stretchable substrate laminate 10A. Furthermore, a plurality of stretchable wirings 20α (i.e., stretchable wirings 20 not having the first portion 21 and the second portion 23) are provided in stretchable substrates 10 other than the stretchable substrate 10 on which the electronic component 70 is mounted (i.e., stretchable substrates 10 other than the uppermost layer and / or the lowermost layer). Such stretchable wirings 20α may extend in a first direction and / or a second direction different from the first direction.

[0101] The stretchable wiring 20 having a first portion 21 and a second portion 23 and provided inside the stretchable substrate 10 on which the electronic component 70 is mounted can be electrically connected to a stretchable wiring 20α provided on another stretchable substrate 10. These stretchable wirings 20, 20α may be connected via another stretchable wiring 20α, or a stretchable wiring 20 that can function as a conductive portion may be connected instead of the via conductor 28. Similarly, multiple stretchable wirings 20α provided on stretchable substrates 10 other than the stretchable substrate 10 on which the electronic component 70 is mounted may also be connected to each other via the stretchable wiring 20α and / or instead of the via conductor 28. Note that the via conductor 28 has in common with the second portion 23 of the stretchable wiring in that it acts as a "conductive portion." Therefore, in the present specification, it is clearly stated that the via conductor 28 may be part of the constituent elements of the stretchable wiring 20.

[0102] By stacking the stretchable substrate 10 having the stretchable wirings 20, 20α arranged as described above, multilayer wiring becomes possible, and high integration can be achieved. Furthermore, the stacked structure optimizes the interaction between layers, improving electrical connection performance and mechanical strength. Furthermore, by adopting a stacked structure, stress during stretching is distributed to each layer, and the mechanical strength and durability of the stretchable device 200 can be further enhanced compared to the first embodiment.

[0103] On the other hand, in a conventional configuration, if a part of a stretchable substrate on which an electronic component is mounted has a recess and a stretchable substrate without a recess is laminated underneath, the stretchability of the stretchable device may differ depending on whether or not the recess exists. In such a configuration, stress tends to concentrate around the recess, and there is a risk that, for example, some of the multiple wirings may be broken, making it impossible to ensure electrical connection of the stretchable device.

[0104] In contrast, the stretchable substrate laminate 10A according to the present disclosure is composed of a plurality of stretchable substrates 10 that do not have recesses, and therefore the thickness of each stretchable substrate 10 is uniform. With this configuration, even when the stretchable device 200 stretches or contracts, the stretchability of each stretchable substrate 10 is equal, and it is possible to prevent stress from concentrating at a specific location. As a result, it is possible to prevent breakage of the stretchable substrate 10 and the stretchable wirings 20, 20α on which the electronic component 70 is mounted, which can contribute to improving the reliability of the stretchable device 200.

[0105] 13A to 13C, the configuration of a stretchable device according to the eighth embodiment will be described. Compared to the first embodiment, the eighth embodiment differs in that a stretchable substrate laminate 10A is configured in which a plurality of stretchable substrates 10 are laminated in the thickness direction. Another difference is that a surface electrode 27 is provided on the end face 24 of the second portion of the stretchable wiring 20, and the surface electrode 27 is connected to an electronic component 70.

[0106] Fig. 13A is a top view schematically showing a stretchable device (electronic component mounted state) according to an eighth embodiment of the present disclosure. Fig. 13B is a cross-sectional view (at cross section XIIIB-XIIIB in Fig. 13A) schematically showing a stretchable device (electronic component mounted state) according to the eighth embodiment of the present disclosure. Fig. 13C is an enlarged view of a connection portion between an electronic component and a stretchable substrate in a stretchable device according to the eighth embodiment of the present disclosure.

[0107] Furthermore, when producing the stretchable device of the eighth embodiment, it differs from the production method of the first embodiment in that it includes a step of stacking a plurality of stretchable substrates 10, a step of providing a plurality of stretchable wirings 20, 20α as the stretchable substrates 10 are stacked, and a step of producing a surface electrode 27 on the end face 24 of the second portion 23 of the stretchable wiring 20. By producing using this method, it is possible to produce the stretchable device 200 according to the eighth embodiment, which constitutes a stretchable substrate laminate 10A in which a plurality of stretchable substrates 10 are stacked in the thickness direction.

[0108] The stretchable device 200 according to the eighth embodiment of the present disclosure includes an electronic component 70, a plurality of stretchable substrates 10, and stretchable wirings 20, 20α, and constitutes a stretchable substrate laminate 10A in which a plurality of stretchable substrates 10 are laminated in the thickness direction. The stretchable device 200 further includes a surface electrode 27 on an end surface 24 of the stretchable wiring 20.

[0109] Specifically, a surface electrode 27 is further provided on the end surface 24 of the second portion 23 of the stretchable wiring 20 provided on the stretchable substrate 10 on which the electronic component 70 is mounted, and the surface electrode 27 is connectable to the electronic component 70. The surface electrode 27 is preferably provided on the end surface 24 of the stretchable wiring 20, but may be partially embedded in the thickness direction of the end surface 24. When the surface electrode 27 is provided on the end surface 24, connection with the stretchable substrate 10 is ensured, maintaining the stability of the electrical connection, and being disposed on the end surface 24 simplifies the manufacturing process. Furthermore, the surface electrode 27 disposed on the end surface 24 is easily accessible as an external connection portion. When the surface electrode 27 is partially embedded in the end surface 24 of the stretchable wiring 20, it is at least embedded in the stretchable substrate 10, and the surface electrode 27 can be integrated with the stretchable substrate 10. Therefore, stress during expansion and contraction is dispersed, improving the durability of the electrode structure and suppressing failures such as peeling.

[0110] In particular, when the electronic component 70 is mounted on the surface electrode 27, the electronic component 70 is connected to the stretchable substrate 10 and the stretchable wiring 20 via a connection member 90 (for example, solder, etc.), and therefore stress is likely to concentrate on the outer edge of the connection portion with the surface electrode 27. However, by adopting the configuration of the present disclosure, it is possible to alleviate the concentration of stress on the outer edge when the stretchable device 200 stretches and contracts, and to increase the reliability of the connection portion with the electronic component 70.

[0111] Furthermore, the outer contour of the end surface 24 of the second portion of the stretchable wiring 20 may coincide with the outer contour of the surface electrode 27 when viewed from above, or may be outside the outer contour of the surface electrode 27. With such a configuration, the surface electrode 27 is supported by the end surface 24 of the stretchable wiring 20, thereby improving mechanical stability and further promoting the stress dispersion effect. This suppresses stress concentration at the connection with the electronic component 70, potentially reducing defects such as peeling and breakage. Furthermore, by ensuring a sufficient contact area with the stretchable wiring 20, the reliability of the electrical connection is improved, and further, stable performance can be more easily ensured even against variations such as misalignment during the manufacturing process.

[0112] In the seventh embodiment, as described above, the via conductor 28 can be part of the constituent elements of the stretchable wiring 20, and therefore the second portion 23 of the stretchable wiring 20 may be replaced with the via conductor 28, or the via conductor 28 and the first portion 21 of the stretchable wiring 20 may be continuous to form the stretchable wiring 20 (see FIG. 11 ). Similarly, in the eighth embodiment, the via conductor 28 can be part of the constituent elements of the stretchable wiring 20, and a configuration can be adopted in which a surface electrode 27 is provided on the via conductor 28. Whichever configuration is adopted, the desired effect, such as electrical connection, can be obtained.

[0113] Example 1 + Comparative Example 1 A comparative experiment was carried out using a conventional stretchable device (having a step on the device's main surface / having a recessed portion with a space in which electronic components can be placed inside) and the stretchable device 100 of the present disclosure (having no step on the device's main surface).

[0114] First, both end holding portions of each test piece on which an LED (corresponding to electronic component 70) was mounted were fixed to a tensile testing machine (Japan Measurement Systems Co., Ltd., model number: JSH-H1000), and then a voltage was applied to the stretchable substrate portion of the test piece to light up the LED.

[0115] Thereafter, the stretchable device 100 was stretched using a tensile tester. The length of each test piece was measured when the LED went out, that is, when the stretchable wiring was broken, and the stretch rate of the stretchable device after stretching relative to the initial length before stretching was calculated.

[0116] The results are shown in Figure 8. The left side of Figure 8 shows the results for the conventional stretchable device, and the right side shows the results for the stretchable device 100 of the present disclosure. The stretch rate was approximately 20% for the conventional structure, while it was approximately 35% for the structure of the present disclosure. This demonstrates that the stretch rate was improved by approximately 15%, and that breakage of the stretchable wiring 20 could be suppressed.

[0117] Example 2 + Comparative Example 2 In order to further confirm the above tensile test experiment numerically or visually, a structural analysis was carried out using drawings that three-dimensionally represent the structures of the prior art and the present disclosure.

[0118] As a result, in the conventional structure, stress was locally applied to the stretchable wiring 20 exposed from the step portion, and the stress was approximately 60 MPa. On the other hand, in the structure of the present disclosure, although stress was applied to the interface where the electronic component 70 and the stretchable substrate 10 contact, the stress was approximately 20 MPa, and it was confirmed that the applied stress was reduced to one-third compared to the conventional structure.

[0119] Furthermore, it was revealed that the stress applied to the conventional structure was greater over a wider range than the structure of the present disclosure. From the above, it was confirmed that, according to the structure of the present disclosure, the exposed portion of the conventional stretchable wiring 20 is covered by the stretchable substrate 10, and the stress applied to the stretchable wiring 20 is dispersed to the covered stretchable substrate 10, thereby alleviating the stress. It can be said that the results of this structural analysis are consistent with the results of the above-mentioned tensile test.

[0120] Although the embodiments of the present disclosure have been described above, they are merely typical examples. Those skilled in the art will readily understand that the present disclosure is not limited thereto, and that various modifications are possible within the scope of the present disclosure.

[0121] The stretchable device according to an embodiment of the present disclosure as described above includes the following preferred aspects. First aspect: A stretchable device comprising: a stretchable substrate; an electronic component mounted on the stretchable substrate; and a plurality of stretchable wirings provided at least within the stretchable substrate, wherein the stretchable substrate has a first region overlapping the stretchable wiring when viewed from the thickness direction, and a second region not overlapping the stretchable wiring but overlapping the electronic component, and wherein, in a cross-sectional view at a location where the stretchable wiring is arranged, the thickness of the second region is greater than the thickness of the first region, and at least one of the plurality of stretchable wirings has a first portion extending in a first direction which is the stretch direction of the stretchable wiring, and a second portion extending in a second direction different from the first direction, which is continuous with the first portion and can be electrically connected to the electronic component. Second aspect: A stretchable device in the above first aspect, wherein the stretchable wiring has a bent form. Third aspect: A stretchable device in the above first aspect or the above second aspect, wherein the second portion of the stretchable wiring and the second region of the stretchable substrate are in contact with each other. Fourth aspect: A stretchable device according to any one of the first to third aspects, wherein a side surface that is continuous with the end face of the second portion and extends in the thickness direction of the stretchable substrate is flush with a side surface of the electronic component. Fifth aspect: A stretchable device according to any one of the first to fourth aspects, wherein the thickness of the second portion of the stretchable wiring is greater than the thickness of the first portion. Sixth aspect: A stretchable device according to any one of the first to fifth aspects, wherein the end face of the second portion of the stretchable wiring is located on the uppermost surface of the stretchable substrate or is located above the uppermost surface. Seventh aspect: A stretchable device according to the sixth aspect, wherein the main surface of the stretchable substrate is on the same plane without any steps. Eighth aspect: A stretchable device according to any one of the first to seventh aspects, wherein a part of the first portion of the stretchable wiring is exposed in the stretching direction. Ninth aspect: A stretchable device according to any one of the first to eighth aspects, wherein the exposed part of the first portion is used as an electrode. Tenth Aspect: The stretchable device according to any one of the first to ninth aspects, further comprising a stretchable substrate cover member that covers the stretchable substrate and the stretchable wiring.11th Aspect: The stretchable device according to any one of the first to ninth aspects, further comprising a light-shielding sheet or a heat-insulating sheet that covers the stretchable substrate and the stretchable wiring. 12th Aspect: The stretchable device according to any one of the first to ninth aspects, further comprising a color sheet that covers the stretchable substrate and the stretchable wiring. 13th Aspect: The stretchable device according to any one of the first to twelfth aspects, further comprising an electronic component cover member that covers the electronic components. 14th Aspect: The stretchable device according to any one of the first to thirteenth aspects, further comprising a sealant that surrounds the electronic components on a main surface of the stretchable substrate. 15th Aspect: The stretchable device according to the fourteenth aspect, wherein the Young's modulus of the sealant is greater than the Young's modulus of the stretchable substrate. 16th Aspect: The stretchable device according to the fourteenth or fifteenth aspect, wherein the Young's modulus of the sealant is 300 MPa or more. 17th Aspect: The stretchable device according to any one of the 14th to 16th aspects, wherein, in a plan view, an outer contour of the sealing material is outside an outer contour of the electronic component. 18th Aspect: The stretchable device according to any one of the 1st to 17th aspects, comprising a stretchable substrate laminate in which a plurality of the stretchable substrates are laminated in the thickness direction, wherein the stretchable wiring having the first portion and the second portion is provided at least inside the stretchable substrate on which the electronic component is mounted, and a plurality of stretchable wirings are provided on the stretchable substrate other than the stretchable substrate on which the electronic component is mounted, and the stretchable wiring having the first portion and the second portion is electrically connectable to the stretchable wiring provided on the other stretchable substrate. 19th Aspect: The stretchable device according to any one of the 1st to 18th aspects, further comprising a surface electrode on an end face of the second portion of the stretchable wiring, and the surface electrode is connected to the electronic component. 20th Aspect: The stretchable device of the 19th aspect, wherein, in plan view, the outer contour of the end face of the second portion of the stretchable wiring coincides with the outer contour of the surface electrode or is outside the outer contour of the surface electrode.

[0122] 100: Stretchable device 200: Stretchable device 1: First main surface 2: Side surface 3: Second main surface 4: Through-hole 10: Stretchable substrate 10A: Stretchable substrate laminate 11: First region of stretchable substrate 12: Second region of stretchable substrate 13: Third region of stretchable substrate 20: Stretchable wiring 20α: Stretchable wiring 21: First part of stretchable wiring 22: Part of the first part of the stretchable wiring 23: Second part of the stretchable wiring 24: End face of the second part of the stretchable wiring 25: Electrode 26: Side surface of the second part 23 of the stretchable wiring 27: Surface electrode 28: Via conductor 30: Stretchable substrate cover member 40: Light-shielding sheet 70: Electronic component 80: Electronic component cover member 90: Connection member 91: Sealant

Claims

1. A stretchable device comprising: a stretchable substrate; an electronic component mounted on the stretchable substrate; and a plurality of stretchable wirings provided at least within the stretchable substrate, wherein the stretchable substrate has a first region that overlaps with the stretchable wiring when viewed from the thickness direction, and a second region that does not overlap with the stretchable wiring but overlaps with the electronic component, and wherein, in a cross-sectional view at the location where the stretchable wiring is arranged, the thickness of the second region is greater than the thickness of the first region, and at least one of the plurality of stretchable wirings has a first portion that extends in a first direction that is the stretch direction of the stretchable wiring, and a second portion that is continuous with the first portion and extends in a second direction different from the first direction so as to be electrically connectable to the electronic component.

2. The stretchable device according to claim 1, wherein the stretchable wiring has a bent configuration.

3. The stretchable device according to claim 1 or 2, wherein the second portion of the stretchable wiring and the second region of the stretchable substrate are in contact.

4. A stretchable device according to any one of claims 1 to 3, wherein a side surface of the stretchable wiring that is continuous with the end surface of the second portion and extends in the thickness direction of the stretchable substrate is flush with a side surface of the electronic component.

5. The stretchable device according to any one of claims 1 to 4, wherein the thickness of the second portion of the stretchable wiring is greater than the thickness of the first portion.

6. A stretchable device according to any one of claims 1 to 5, wherein the end face of the second part of the stretchable wiring is located on the uppermost surface of the stretchable substrate or above the uppermost surface.

7. The stretchable device according to claim 6, wherein the main surface of the stretchable substrate is flush with the surface.

8. The stretchable device according to any one of claims 1 to 7, wherein a part of the first part of the stretchable wiring is exposed in the stretching direction.

9. The stretchable device according to any one of claims 1 to 8, wherein the partially exposed portion of the first part is used as an electrode.

10. The stretchable device according to any one of claims 1 to 9, further comprising a stretchable substrate cover member that covers the stretchable substrate and the stretchable wiring.

11. The stretchable device according to any one of claims 1 to 9, further comprising a light-shielding sheet or a heat-insulating sheet that covers the stretchable substrate and the stretchable wiring.

12. The stretchable device according to any one of claims 1 to 9, further comprising a color sheet that covers the stretchable substrate and the stretchable wiring.

13. The stretchable device according to any one of claims 1 to 12, further comprising an electronic component cover member that covers the electronic component.

14. The stretchable device according to any one of claims 1 to 13, further comprising a sealing material on a main surface of the stretchable substrate that surrounds the electronic component.

15. The stretchable device of claim 14, wherein the encapsulant has a Young's modulus greater than the Young's modulus of the stretchable substrate.

16. The stretchable device according to claim 14 or 15, wherein the Young's modulus of the encapsulant is 300 MPa or more.

17. The stretchable device according to any one of claims 14 to 16, wherein, in a plan view, the outer contour of the sealing material is outside the outer contour of the electronic component.

18. A stretchable device according to any one of claims 1 to 17, comprising a stretchable substrate laminate in which a plurality of the stretchable substrates are laminated in the thickness direction, the stretchable wiring having the first portion and the second portion is provided at least inside the stretchable substrate on which the electronic component is mounted, a plurality of stretchable wirings are provided on the stretchable substrate other than the stretchable substrate on which the electronic component is mounted, and the stretchable wiring having the first portion and the second portion is electrically connectable to the stretchable wiring provided on the other stretchable substrate.

19. The stretchable device according to any one of claims 1 to 18, further comprising a surface electrode on an end surface of the second portion of the stretchable wiring, the surface electrode being connected to the electronic component.

20. The stretchable device according to claim 19, wherein, in a plan view, the outer contour of the end face of the second portion of the stretchable wiring coincides with the outer contour of the surface electrode or is outside the outer contour of the surface electrode.

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